1. Field of the Invention
This invention relates to an electronic thermometer having means for prediciting a converged or steady temperature based on a measured temperature, and more particularly to an improved clinical thermometer including means for alarming that the predicting means is inoperable.
2. Discussion of the Prior Art
There is conventionally known an electronic clinical thermometer so designed that a body temperature is sensed by a temperature sensor, the sensed temperature is read by a processing unit, such as CPU or the like, on a predetermined sampling cycle to be displayed, while a converged temperature is predicted according to the sensed temperature to be displayed instead of the sensed temperature. After obtaining a predetermined volume off data about the sensed temperature, the converged temperature is subsequently renewed until completion of the measurement so as to improve the accuracy of the measurement, but when the sensed temperature suddenly drops, the predicting operation is judged to be impossible so that an indication of an operation error is displayed.
The judgement that the predicting operation is impossible is performed only when the degree of the drop of the temperature becomes larger than a predetermined value, for example, in the event that the temperature sensor is fairly out of measuring position. The conventional electronic thermometer in the event that the temperature sensor is slightly shifting from the measuring position, however, continues to compute out a converged temperature to be displayed by judging that the predicting operation is possible since the sensed temperature drops within a certain degree, so that the measurement is finished continuing erroneous prediction which results in a low reliability.